The present invention relates to a compact gas (e.g., carbon monoxide) sensor formed at least partially of a thin film material such as silicon.
Carbon monoxide (CO) is an example of a gas of interest to be sensed, as it is a colorless, odorless, highly toxic gas that is dangerous to humans at fairly low concentrations. CO is a commonly generated gas during early stages of combustion or heating of various materials. Detecting CO (or other gases) can be accomplished using numerous techniques including spectroscopy, electrochemical sensing, and metal oxide semiconductor (MOS) devices. Existing electrochemical CO sensors provide high performance but are relatively bulky.
Miniature devices fabricated from semiconductor materials such as silicon have become known as micro-electro-mechanical systems (MEMS). MEMS processing techniques allow fabrication of very small devices with high resolution.